Improvement in machines for grinding circular saws



JOHN PEDDE'R & GEORGE ABEL.

Improvement in Machines fer Grinding Circular Saws.

N0. 118,482. Patented Aug. 29,1871.

aw-4 4 Q8572 I 21 411mm Mari/m Him? UNITED STATES PATENT OFFICE.

JOHN PEDDER AND GEORGE ABEL, OF TEMPERANOEVILLE, PENNSYLVANIA.

IMPROVEMENT IN MACHINES FOR GRINDING CIRCULAR SAWS.

Specification forming part of Letters Patent No. 118,482, dated August 29, 1871.

had to the accompanying drawing making a part' of this specification, in which- Figure 1 is a top or plan View of our machine, and Fig. 2 is a side elevation thereof.

Like letters of reference indicate like parts in each.

Our invention relates to an improvement in machines for grinding the opposite faces or sides of circular metallic blanks, such as circular saws, plow-colters, 850. By it we are enabled to grind both faces at the same time of blanks of different thicknesses and diiferent diameters, and to shift their position so that they may be ground at all points from center to circumference without nec essarily stopping the motion of the machine.

To enable othersskilled in the art to make and use our improvement, we will proceed to describe its contruction and mode of operation.

The frame-work B is of any suitable material or construction. The blank a to be ground is fastened to the endof a mandrel or blank-holder, b, which is set in plumber-blocks b so that it may have a rotary motion, which motion is produced by a crank or band-wheel, m, or otherwise, at pleasure. The plumber-blocks I) rest on a reciprocating slide, N, which is guided by a projecting guide, g, playing in the slot of the bed B. This slide-rest 1) moves in a direction at right angles to the line of the mandrel b. It may be operated back and forth in any suitable way but, as shown in the drawing, it is shifted bya lever, 9 arranged below the bed B, and connected to the guide g. By this lever a reciprocating motion or travel may, through the rest b plumber-blocks b and mandrel I), be given to the blank to so as to make it travel laterally back and forth between the grindstones or grinding-wheels c, which latter are thereby caused to grind it at all points, or any point from, at, or near its center to its circumference. The blank a should at the same time be rotated so that the grinding may be uniform over all parts of its faces. The grindstones or grinding-wheels c c c c are arranged in pairs,

as shown, so that the grinding-faces of each pair shall operate against each other on the opposite faces of the blank a, as shown. Each grindstone is hung on a shaft, 0 which latter is mounted 011 plumber-blocks 0 Each pair of plumber-blocks c is carried by a sliding rest, h, which is guided in its travel to and from the blank a by sliding ways or other suitable guides. The springs h are properly arranged to press the grinding wheels 0 up to their work and adapt the machine to grinding blanks of different thicknesses.

Power is applied by means of band-wheels d arranged on the shafts 0 In order to be able to open or separate the grindingwheels 0 so as to insert or take out blanks, as well as in order to limit the depth of the grinding action, we arrange between each pair of rests h a double cam or eccentric, a, with an end or eccentric part bearing against each rest. These cams are fastened each to a camshaft which projects down through the bed of the frame B, and to the lower end of which is fastened a crank-lever, e, as shown in dotted lines in Fig.1. These crank-arms are connected at their outer ends by a connecting-bar, 6 also shown in dotted lines, so that any motion imparted to one will equally shift the other. From this bar 6 a handle, 6 projects above the bed of the frame B so as to be within reach of the operator. Any suitable locking device may becombined therewith so as to hold the grinding-wheels c at any desired distance apart.

To separate the wheels 0 the operator has merely to move the handle 0 so as to bring the heads or working-faces of the cams it against the sliding rests h and press them back.

Like devices may be used for polishing as well as grinding circular metallic blanks. Also, flat grinding disks may be substituted for the grind- 'ing-wheels.

What we claim as our invention, and desire to secure by Letters Patent, is-

1. One or more pairs of grinding or polishingwheels or disks, each pair'having its grinding or operative points opposite, and susceptible of motion to or from each other at pleasure, in combination with a blank-holder or mandrel so arranged as to be capable of a horizontal motion at right angles to the plane of the revolving wheels, substantially as described.

2. The blank-holder, so made as to be rotated pressing devices for keeping the wheels up to their work, arranged substantiallyas described.

In testimony whereof we, the said JOHN PED- DER and GEORGE ABEL, have hereunto set our hands.

JOHN PEDDER. Witnesses: GEO. ABEL.

W. N. PAXToN,

G. H. OI-IRIsTY. 

